Index. 295 



Citric acid, nature and properties of, ii. 165. 



Civil day, commencement of the, ii. 15. 



Clays, account of, ii. 183. 



Clouds, how formed, i. Q2, 93. 



Cohabation, an absurd term; its meaning, ii. 101. 



Cohesion, attraction of, i. 11. Hi experiments illustrative 

 of this attraction, 18, lg. 



Cold, reason of thai-felt on approaching mountains of ice, 

 ii. 64 at the tops of mountains, 65. 



Cold blooded animals, experiments with galvanism on, i. 

 191. 



Colours, lecture on, i. 199 they do not reside in the ob- 

 jects themselves, but in the light, ib. illustration of 

 this remark, 200 light first analysed, and separated 

 into the different colours, by Newton ; his experiments 

 with the prism, 200, 201 the theory of colours thus 

 completely unfolded, 205 beauty of a single prismatic 

 ray, 206 explanation of the phenomenon of the rain- 

 bow, 207 principle of semipellucid bodies, 211 the 

 blue colour of the sky and the green colour of the sea 

 accounted for, 212. 



Colures, circles so called, i. 268. 



Combustible, substances how rendered, from which the 

 oxygen has been taken away, ii. 86. 



Combustible substances, lecture on, ii. IQS explanation 

 of the phenomenon of combustion, ib. combustibles 

 divided into fixed and volatile, lQ(j also into simple 

 and compound : account of the different kinds of the 

 simple, 200. 248 of the compound, 209 to 223. 



Combustion, canon of chemistry concerning, ii. 42 is 

 one of the more general effects of caloric, 83 distinc- 

 tion between combustible and incombustible bodies, ib. 

 the latter class ready to receive caloric, and give it out 

 again in equal quantity, 83, 84 the cases of inflamed 

 spirit of wine and sulphur no exception to this assertion, 

 84, 85 combustion consists of a decomposition and a 

 combination, 86. 



Comets, account of, i. 308. 



Compass, mariner's, its great utility, i. 26 variation of 



the compass explained, 27 dip of the needle, 30. 

 Concave mirrors, phenomena of, i. 172 to 177 optical 

 deceptions practised with, 175. 



Condensing syringe, principle of this instrument, i. 79. 



